Comparative investigation of silicone rubber composite and room temperature vulcanized coated glass insulators installed in coastal overhead transmission lines

The fault-free performance of outdoor insulators is a matter of great importance for power utilities as a single insulator fault may lead to an extended outage. Several factors related to operation conditions affect the performance of outdoor insulators, with pollution being probably the most significant one [1]-[3]. Coastal areas are considered heavily polluted due to the deposition of sea salt on the insulators. When the deposited salt is diluted in water through humidity, drizzle, fog, or light rain, a conductive solution is created and leakage current flows on the surface. The activity may advance, under favorable conditions, to flashover. Therefore, the local weather and climate is an important factor for the determination of pollution severity as strong winds carry more salt and frequent rains may provide natural cleaning.